* {
    font-family: Arial;
}

body {
    background: -moz-linear-gradient(top,  rgba(238,238,238,0.7) 0%, rgba(238,238,238,0.7) 100%); /* FF3.6+ */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(238,238,238,0.7)), color-stop(100%,rgba(238,238,238,0.7))); /* Chrome,Safari4+ */
    background: -webkit-linear-gradient(top,  rgba(238,238,238,0.7) 0%,rgba(238,238,238,0.7) 100%); /* Chrome10+,Safari5.1+ */
    background: -o-linear-gradient(top,  rgba(238,238,238,0.7) 0%,rgba(238,238,238,0.7) 100%); /* Opera 11.10+ */
    background: -ms-linear-gradient(top,  rgba(238,238,238,0.7) 0%,rgba(238,238,238,0.7) 100%); /* IE10+ */
    background: linear-gradient(to bottom,  rgba(238,238,238,0.7) 0%,rgba(238,238,238,0.7) 100%); /* W3C */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#b3eeeeee', endColorstr='#b3eeeeee',GradientType=0 ); /* IE6-9 */
    padding: 0;
    margin: 0;
}

#main{
    width: 1000px;
    padding: 10px;
    margin: auto;
    background-color: white;
}

#descripcion{
     
}

nav#temas li{
    width: 80%;
    margin: 15px 8% 15px 8%;
    background-color: green; 
    height: 150px;
    list-style: none;
}

#tematica {
    width: 90%;
    margin: 15px 5% 15px 4%;
    background-color: green; 
    height: 600px; 
}
